Shorten Decode Test Time

This commit reduces the number of frames used in DecodeMultiThreaded
tests to reduce test time.

Change-Id: I4072350c0aa4d19b0d4386ea4de38bcdb9e2ded0
diff --git a/test/decode_multithreaded_test.cc b/test/decode_multithreaded_test.cc
index 92253ed..0aa7eb0 100644
--- a/test/decode_multithreaded_test.cc
+++ b/test/decode_multithreaded_test.cc
@@ -111,7 +111,7 @@
     cfg_.rc_end_usage = AOM_VBR;
 
     libaom_test::I420VideoSource video("hantro_collage_w352h288.yuv", 704, 576,
-                                       timebase.den, timebase.num, 0, 5);
+                                       timebase.den, timebase.num, 0, 2);
     ASSERT_NO_FATAL_FAILURE(RunLoop(&video));
 
     const char *md5_single_thread_str = md5_single_thread_.Get();